US withdrawal from Kyoto has angered many Europeans
Talks in the German city of Bonn on salvaging the global climate treaty appear to be running into trouble.
A third day of discussions by officials has
brought little sign of any real progress before
ministers arrive on Wednesday.
Some countries want to reopen questions that were supposed to have been resolved months ago.
As one observer put it: "Bonn is adrift."
A European Union (EU) official told BBC News Online: "If the political will were there you could cut through the outstanding issues.
"But what we're seeing is a hardening of positions by some countries.
"The talks certainly aren't going forwards at all. They're either stagnant, or moving backwards."
Emissions target
The talks are a resumption of the negotiations which collapsed in The Hague last November on finalising the workings of the Kyoto Protocol.
This requires industrialised countries to cut their emissions of greenhouse gases by an average of 5.2% below their 1990 levels by 2012.
But the US, the world's biggest
polluter, pulled out of the treaty last March, and the
Bonn talks are trying to find a way for the remaining
signatories to ratify it.
The hope is that it will enter into force in 2002.
Unless Japan agrees to ratify the protocol, there will be too few of the main polluting countries supporting it to allow its entry into force.
But Japan, unwilling to ratify Kyoto without the support of its close ally the US, is trying to extract far-reaching concessions as the price for its adherence.
It is pressing to be allowed to make more use than other countries of what are called "carbon sinks" - forests, grassland and other vegetation which absorbs carbon dioxide, and can be counted against a country's emissions reduction target.
Nuclear argument
It is also resisting all the proposals currently on the table about securing compliance with the protocol.
The Hague meeting reached broad agreement that nuclear power projects should not be part of the treaty's Clean Development Mechanism (CDM).
This allows industrialised countries to finance emissions-reducing projects in developing countries and then to claim credits against their own targets.
Impossible situation
But the three countries now say nuclear power should be included in the CDM after all.
What worries many people here is the prospect that the high-level political session of the talks, due to start late on Wednesday, will land ministers in an almost impossible situation.
Without rapid progress over the next 24 hours, the ministers will have to try to find all the answers that have so far eluded their delegations.
And they have only until the evening of 22 July to do it.
Kate Hampton, of Friends of the Earth International, told BBC News Online: "Delegates are depressed - they need political leadership and commitment.
"But it's hard to see who's providing any leadership here.
"There is barely any process in place for making progress on the sticky issues - finance, compliance, sinks, and the mechanisms for buying and selling emission rights.
"Bonn is adrift. At the moment it's moving backwards - nobody wants to stick their head out, or to compromise.
"The ministers shouldn't have to come here and invent a process to let them do their job. That'll make it very difficult for them to find agreement.
"I think the outcome will depend very much on the G8 meeting in Genoa. We're looking to Tony Blair, Gerhard Schroeder and Jacques Chirac in particular to send a clear message to their ministers here that they must conclude a deal."
There is a more optimistic view on offer - that Bonn will decide little, but will at least keep the Kyoto Protocol alive until the next scheduled round of negotiations in Morocco in October.
The die-hard optimists also think Bonn will keep Japanese support for the treaty intact.